CN110645058B - Turboset transient torque protection method and device based on shafting rotating speed - Google Patents

Abstract

The invention discloses a method and a device for protecting transient torque of a steam turbine set based on shafting rotating speed, wherein the method comprises the following steps: filtering the rotating speed signal of the shafting of the unit by using a filter to obtain the current modal rotating speed of the unit; performing transient torque identification by using the current modal rotating speed to obtain a transient torque identification value; if the current modal rotating speed is larger than a first preset value, judging whether the transient torque identification value is larger than a second preset value; and if the transient torque identification value is larger than the second preset value and is in a continuous increasing state, a tripping command is sent out to cut off the current unit. The method can avoid damage to the shafting of the turbine generator set due to overlarge torque, ensure the safety of the shafting of the turbine generator set and effectively solve the SSR problem between the turbine generator set and the series capacitance compensation power transmission network.

Description

Transient torque protection method and device for steam turbine unit based on shafting speed

technical field

The invention relates to the technical field of power system protection, in particular to a method and device for transient torque protection of a steam turbine set based on shafting speed.

Background technique

Long-distance and large-capacity power transmission is an objective requirement for the development of my country's power industry. In order to improve the transmission capacity of long-distance transmission lines and improve the stability of the system, series capacitor compensation technology has been more and more widely used. However, the interaction between the turbo-generator set and the series capacitor compensation transmission network will cause a stability problem in the subsynchronous frequency range, that is, the subsynchronous resonance (SSR) problem. When the SSR problem occurs, high transient torque and stress will be generated between the mass blocks of the shafting of the unit, resulting in loss of fatigue life and reducing the service life of the shafting of the unit; in extreme cases, the transient torque of the shafting of the unit is too large or even It will cause the large shaft of the unit to break, resulting in serious equipment and even personal safety accidents.

In order to ensure the safety of the shafting of the steam turbine generator set, and ensure that the shafting of the unit will not suffer from excessive fatigue life loss and the problem of one-time fracture of the large shaft of the unit when the SSR problem occurs, the existing research has proposed some protection methods. Such as TSR (Torsional stress relay, torsional vibration relay). However, TSR has a long delay in response (about 0.5s), which cannot reflect the impact torque generated by the shaft system when the unit occurs SSR, and can only play a role when the unit torque diverges. However, if the impact torque of the unit is too large, the fatigue life loss of the shafting of the unit will be too large, and even the large shaft of the unit will be broken at one time. Therefore, it is necessary to develop a transient torque protection technology and device with faster response and higher reliability.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

Therefore, an object of the present invention is to propose a transient torque protection method for a steam turbine unit based on the shafting speed, which can avoid damage to the shafting of the unit due to excessive torque, ensure the safety of the shafting of the steam turbine generator, and effectively solve the problem. SSR problem between steam turbine unit and series capacitor compensation transmission network.

Another object of the present invention is to provide a transient torque protection device for a steam turbine set based on shafting speed.

In order to achieve the above purpose, an embodiment of the present invention proposes a transient torque protection method for a steam turbine unit based on shafting speed, including the following steps: using a filter to filter the shafting speed signal of the unit to obtain the current mode of the unit. speed; use the current modal speed to perform transient torque identification to obtain a transient torque identification value; if the current modal speed is greater than the first preset value, determine whether the transient torque identification value is greater than the second preset value; if If the transient torque identification value is greater than the second preset value and is in a state of continuous increase, a trip command is issued to cut off the current unit.

The shafting speed-based transient torque protection method for a steam turbine set according to the embodiment of the present invention is based on modal speed acquisition and transient torque identification. First, a filter is used to filter the shafting speed of the unit to obtain the modal speed of the unit; then , use the torque identification link to obtain the transient torque of the unit; finally, use the protection criterion to determine whether to send a trip command to disconnect the unit from the power grid, so as to avoid the damage to the shaft system of the unit caused by excessive torque and ensure the shaft system of the turbo-generator unit. Safely and effectively solve the SSR problem between the steam turbine unit and the series capacitor compensation transmission network.

In addition, the transient torque protection method for a steam turbine unit based on the shafting speed according to the above embodiment of the present invention may also have the following additional technical features:

Further, in an embodiment of the present invention, if the transient torque identification value is greater than the second preset value and is in a state of continuous increase, issuing a trip command includes: judging the transient torque identification value Whether it is greater than the second preset value; if it is greater than the second preset value, delay one cycle to judge whether it is a continuous growth state according to the current cycle torque peak value and the previous cycle peak value; if it is the continuous increase state, the trip command is generated.

Further, in an embodiment of the present invention, the performing transient torque identification according to the current modal rotational speed to obtain a transient torque identification value includes: converting the current modal rotational speed into a shaft system corresponding to torque The modal speed signal of the position; the modal speed signal of the shafting position corresponding to the torque is integrated to obtain the torsion angle corresponding to each mode; the torsion angle corresponding to each mode is converted into the mass relative to the synchronization The electrical torsion angle of the rotating coordinate system; the torque between each shaft segment is solved according to the electrical torsion angle of the mass relative to the synchronous rotating coordinate system.

Further, in an embodiment of the present invention, the conversion formula of the modal rotational speed signal is:

ω ^(m) = ω./k,

Among them, ω is the current modal speed, ./ is defined as the division of the corresponding elements of the matrix, and k is the coefficient row vector;

Integrate ω ^(m) to obtain the torsion angle δ ^(m) corresponding to each mode;

The conversion formula of the electrical torsion angle is:

[δ ₁ δ ₂ … δ _n-1 δ _n ] ^T = Q·[δ ₁ ^(m) δ ₂ ^(m) … δ _n-1 ^(m) 0] ^T ,

Among them, Q is the coefficient matrix, δ ^(m) is the torsion angle corresponding to each mode, and δ is the electrical torsion angle.

Further, in an embodiment of the present invention, the calculation formula of the torque between the various shaft segments is:

T _ij =K _ij (δ _i -δ _j ),

Among them, K _ij represents the elastic coefficient between each shaft segment.

In order to achieve the above object, another embodiment of the present invention proposes a transient torque protection device for a steam turbine unit based on shafting speed, including: a modal speed acquisition module for filtering the shafting speed signal of the unit by using a filter. , to obtain the current modal speed of the unit; the transient torque identification module is used to perform transient torque identification using the current modal speed to obtain a transient torque identification value; the startup logic module is used to identify the transient torque at the current modal speed When it is greater than the first preset value, determine whether the transient torque identification value is greater than the second preset value; the protection criterion module is used for when the transient torque identification value is greater than the second preset value and is in a state of continuous increase , issue a trip command to cut off the current unit.

The transient torque protection device for a steam turbine unit based on the shafting speed of the embodiment of the present invention is based on the acquisition of the modal speed and the identification of the transient torque. First, a filter is used to filter the shafting speed of the unit to obtain the modal speed of the unit; then , use the torque identification link to obtain the transient torque of the unit; finally, use the protection criterion to determine whether to send a trip command to disconnect the unit from the power grid, so as to avoid the damage to the shaft system of the unit caused by excessive torque and ensure the shaft system of the turbo-generator unit. Safely and effectively solve the SSR problem between the steam turbine unit and the series capacitor compensation transmission network.

In addition, the transient torque protection device for a steam turbine unit based on the shafting speed according to the above embodiment of the present invention may also have the following additional technical features:

Further, in an embodiment of the present invention, the protection criterion module is further configured to determine whether the transient torque identification value is greater than the second preset value; if it is greater than the second preset value, then Delay one cycle to determine whether it is in the continuous growth state according to the current cycle torque peak value and the previous cycle peak value; if it is the continuous growth state, the trip command is generated.

Further, in an embodiment of the present invention, the transient torque identification module is further configured to convert the current modal rotational speed into a modal rotational speed signal of the shafting position corresponding to the torque; Integrate the modal speed signal of the position of the system to obtain the torsion angle corresponding to each mode; convert the torsion angle corresponding to each mode into the electrical torsion angle of the mass relative to the synchronous rotating coordinate system; The electrical torsion angle of the rotating coordinate system solves for the torque between the shaft segments.

Further, in an embodiment of the present invention, the conversion formula of the modal rotational speed signal is:

ω ^(m) = ω./k,

Among them, ω is the current modal speed, ./ is defined as the division of the corresponding elements of the matrix, and k is the coefficient row vector;

Integrate ω ^(m) to obtain the torsion angle δ ^(m) corresponding to each mode;

The conversion formula of the electrical torsion angle is:

[δ ₁ δ ₂ … δ _n-1 δ _n ] ^T = Q·[δ ₁ ^(m) δ ₂ ^(m) … δ _n-1 ^(m) 0] ^T ,

Among them, Q is the coefficient matrix, δ ^(m) is the torsion angle corresponding to each mode, and δ is the electrical torsion angle.

Further, in an embodiment of the present invention, the calculation formula of the torque between the various shaft segments is:

T _ij =K _ij (δ _i -δ _j ),

Among them, K _ij represents the elastic coefficient between each shaft segment.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

1 is a schematic diagram of an overall scheme according to an embodiment of the present invention;

2 is a flowchart of a method for transient torque protection of a steam turbine unit based on shafting speed according to an embodiment of the present invention;

3 is a flowchart of a method for realizing a modal rotational speed link according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a transient torque protection device for a steam turbine unit based on shafting speed according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

The technical solution of the embodiment of the present invention is shown in FIG. 1 , based on modal speed acquisition and transient torque identification, it mainly includes four links: modal speed acquisition, startup logic, transient torque identification and protection criteria.

The basic principle of the realization of the scheme is: modal speed acquisition link: use the speed sensor to obtain the shafting speed of the unit (head or tail speed), filter the speed signal to obtain the modal speed signal of the unit; start the logic link: according to the model Judging whether a start signal is sent from the state speed; Transient torque identification link: use the unit modal speed signal and the transient torque of the unit shafting parameter computer group; Protection criterion link: When the start signal exists, the protection criterion is judged according to the torque identification value Whether a trip command is required. When the transient torque of the shafting of the steam turbine generator set exceeds the preset value and is in a state of continuous growth, the protection device sends a trip command to disconnect the unit from the power grid, so as to avoid the large damage to the shafting of the unit due to excessive torque.

The following describes the method and device for transient torque protection of a steam turbine set based on shafting speed according to the embodiments of the present invention with reference to the accompanying drawings. method of protection.

FIG. 2 is a flowchart of a method for transient torque protection of a steam turbine unit based on shafting speed according to an embodiment of the present invention.

As shown in Figure 2, the transient torque protection method for a steam turbine unit based on shafting speed includes the following steps:

In step S201, a filter is used to filter the rotational speed signal of the shaft system of the unit to obtain the current modal rotational speed of the unit.

It can be understood that, in the embodiment of the present invention, the rotational speed sensor is used to obtain the rotational speed signal, and the filter is used to filter the rotational speed signal of the shaft system of the unit to obtain the modal rotational speed of the unit in each mode.

Specifically, as shown in Figure 1, the modal speed acquisition link

The main function of the modal speed acquisition link is to use the filter to convert the speed pulse signal obtained by the speed sensor into the speed digital signal in each mode. The realization method is shown in Figure 3, including:

(1) Signal conversion

The main function of signal conversion is to convert the pulse quantity of the rotational speed signal obtained by the rotational speed sensor into a digital signal, which is then used for filtering.

(2) Low-pass and high-pass filters

The main function of the low-pass and high-pass filters is to filter out the DC component, low frequency component and power frequency component in the rotational speed signal to ensure that the obtained modal rotational speed is more accurate. The eigenfrequencies of the low-pass and high-pass filters need to "hide" the modal frequency of the power-on unit to ensure that the filtered modal speed signal will not be distorted.

Taking a common steam turbine unit as an example, the characteristic frequency of the high-pass filter can be selected as 10Hz, and the characteristic frequency of the low-pass filter can be selected as 40Hz.

(3) Band-pass, band-stop filter

After the low-pass and high-pass filters filter the speed signal, the modal speed signal in each mode can be obtained after passing through the band-pass and band-stop filters. When designing band-pass and band-stop filters, the characteristic frequency and bandwidth of the filter need to be given. Among them, the characteristic frequency is the modal frequency of the unit; the selection principle of the bandwidth is that the signal obtained by the band-pass and band-reject filters must be the modal speed signal at a single modal frequency. There are a variety of design methods that can be used to design band-pass and band-stop filters. Common design methods include FIR filters, Chebyshev filters, Bessel filters, and elliptic filters.

In addition, a steam turbine unit containing n masses corresponds to n-1 modes in total. The following takes one of the modes as an example to describe the acquisition method of the modal speed signal:

First, the signal is passed through a band-pass filter with ω ₁ as the characteristic frequency to obtain the modal speed signal; then, through the band-stop filter with ω ₂ , ω ₃ ... ω _n-1 as the characteristic frequency, the remaining modal frequencies are eliminated. influence of the signal.

Then, the speed signal is filtered by band-pass and band-stop filters to obtain accurate modal speed signals at each modal frequency.

In step S202, a transient torque identification is performed using the current modal rotational speed to obtain a transient torque identification value.

It can be understood that, after the modal rotational speed is obtained, the embodiment of the present invention performs transient torque identification and determines the startup logic. That is, in this embodiment of the present invention, the modal rotational speed can be used to calculate the transient torque and determine the start-up logic, wherein the start-up logic link will be described in detail below, and will not be described in detail here. Step S202 is the transient torque identification link as shown in FIG. 1 : using the modal rotational speed to solve the torque between each shaft section of the steam turbine unit.

Further, in an embodiment of the present invention, performing transient torque identification according to the current modal rotational speed to obtain a transient torque identification value, including: converting the current modal rotational speed into a modal rotational speed signal of the shafting position corresponding to the torque ; Integrate the modal speed signal of the shaft position corresponding to the torque to obtain the torsion angle corresponding to each mode; convert the torsion angle corresponding to each mode into the electrical torsion angle of the mass relative to the synchronous rotating coordinate system; The block solves for the torque between the shaft segments with respect to the electrical torsion angle of the synchronous rotating coordinate system.

Specifically, the transient torque identification link

The main function of the transient torque identification link is to use the modal speed of the unit and the shaft transient torque of the shaft system parameter computer group. The calculation steps are as follows, taking the current obtained speed signal as the high pressure cylinder speed as an example:

1) Convert the modal speed signal ω at the high-pressure cylinder into the modal speed signal ω ^(m) of the shafting position corresponding to the torque, namely:

ω ^(m) = ω./k (./ is defined as the division of the corresponding elements of the matrix),

ω=[ω ₁ ω ₂ … ω _n-1 0], ω ^(m) =[ω ₁ ^(m) ω ₂ ^(m) … ω _n-1 ^(m) 0],

Among them, the coefficient row vector k is determined by the moment of inertia M and the elastic coefficient K of the shaft system of the unit;

2) Integrate and solve ω ^(m) to obtain the torsion angle δ ^(m) corresponding to each mode;

3) Convert the torsion angle δ ^(m) corresponding to each mode into the electrical torsion angle δ of the mass relative to the synchronous rotating coordinate system, namely:

[δ ₁ δ ₂ … δ _n-1 δ _n ] ^T = Q·[δ ₁ ^(m) δ ₂ ^(m) … δ _n-1 ^(m) 0] ^T ,

Among them, the coefficient matrix Q is determined by the moment of inertia M and the elastic coefficient K of the shaft system of the unit;

4), solve the torque T _ij between each shaft segment, namely:

T _ij =K _ij (δ _i -δ _j ),

Among them, K _ij represents the elastic coefficient between each shaft segment.

Through the above steps, the transient torque of the steam turbine unit can be solved by using the shafting speed.

In step S203, if the current modal rotational speed is greater than the first preset value, it is determined whether the transient torque identification value is greater than the second preset value.

It can be understood that after the startup logic is satisfied, the protection criterion is started, and the current voltage, current and rotational speed of the unit are collected. Specifically: step S203 is the starting logic link shown in FIG. 1 : judging whether the modal speed exceeds the first preset value, and if it exceeds, a starting signal is sent, and it is judged whether the transient torque identification value is greater than the second preset value and is in a continuous state. In the growth state, the current voltage, current and rotational speed of the unit are collected.

Specifically, start the logic link

When the modal speed of the unit is lower than a certain value, the torque between the mass blocks of the shafting of the unit is small, and there is no risk of excessive fatigue loss or damage to the shafting of the unit. In order to reduce the calculation amount of the protection device, a first preset value can be set in the protection device. Only when the modal speed of the unit is higher than the first preset value, the protection device will send a start signal, otherwise it will not send a start signal. Only when the start signal exists, the protection device will determine whether the transient torque identification value is greater than the second preset value and is in a state of continuous increase, and collect the current voltage, current and rotational speed of the unit.

In step S204, if the transient torque identification value is greater than the second preset value and is in a state of continuous increase, a trip command is issued to cut off the current unit.

It can be understood that after detecting the start signal, the protection device starts to collect the current voltage, current and rotational speed of the unit, and performs protection criteria. When the criteria are met, the protection device sends a trip command; when the criteria are not met, the protection device does not act.

Further, in an embodiment of the present invention, if the transient torque identification value is greater than the second preset value and is in a state of continuous growth, issuing a trip command includes: judging whether the transient torque identification value is greater than the second preset value If it is greater than the second preset value, delay one cycle to judge whether it is in a continuous growth state according to the current cycle torque peak value and the previous cycle peak value; if it is a continuous increase state, a trip command is generated.

Specifically, as shown in Figure 1, the protection criteria link

After the start logic sends the start signal, the protection device starts to carry out the protection criterion. When the transient torque identification value of the unit is the second preset value and is in a state of continuous increase, it is determined that the protection criterion is met, and a trip command is issued. The specific implementation method of the criterion is as follows:

First, compare the magnitude of the transient torque identification value and the second preset value. If the identification value is greater than the second preset value, it is determined that the transient torque exceeds the limit; then, delay one cycle to compare the current cycle torque peak value with the previous cycle. The size of the peak value determines whether the transient torque is in a state of continuous growth.

Only when the two are satisfied at the same time, the protection device will issue a trip command to disconnect the unit from the power grid to avoid greater damage to the shaft system of the unit.

To sum up, the embodiment of the present invention firstly uses a filter to filter the shafting speed signal of the unit to obtain the modal speed of the unit; then performs transient torque identification and determines the startup logic; finally, compares the transient torque identification value with the second preset value. The magnitude of the value is used to determine whether the shafting of the unit is at risk of damage or excessive fatigue life loss. If the transient torque identification value exceeds the second preset value and is in a state of continuous growth, the protection device will issue a trip command to quickly cut off the unit to avoid greater damage to the unit due to excessive torque.

According to the shafting speed-based transient torque protection method for a steam turbine set proposed in the embodiment of the present invention, the modal speed acquisition and transient torque identification are based. First, use the filter to filter the shafting speed of the unit to obtain the modal speed of the unit; then, use the torque identification link to obtain the transient torque of the unit; finally, use the protection criterion to determine whether to send a trip command to disconnect the unit from the power grid Therefore, it can avoid the damage to the shaft system of the unit due to excessive torque, ensure the safety of the shaft system of the steam turbine generator set, and effectively solve the SSR problem between the steam turbine unit and the series capacitor compensation transmission network.

Next, the transient torque protection device for a steam turbine set based on shafting speed according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 4 is a transient torque protection device for a steam turbine unit based on shafting speed according to an embodiment of the present invention.

As shown in FIG. 4 , the shafting speed-based transient torque protection device 10 for a steam turbine unit includes: a modal speed acquisition module 100 , a transient torque identification module 200 , a startup logic module 300 and a protection criterion module 400 .

The modal rotational speed acquisition module 100 is used to filter the shafting rotational speed signal of the generator set with a filter to obtain the current modal rotational speed of the generator set; the transient torque identification module 200 is used to identify the transient torque by using the current modal rotational speed, and obtain Transient torque identification value; the activation logic module 300 is used for determining whether the transient torque identification value is greater than the second preset value when the current modal speed is greater than the first preset value; the protection criterion module 400 is used for the transient torque identification value When the identification value is greater than the second preset value and is in a state of continuous growth, a trip command is issued to cut off the current unit. The device 10 in the embodiment of the present invention can avoid damage to the shafting of the unit due to excessive torque, ensure the safety of the shafting of the steam turbine generator set, and effectively solve the SSR problem between the steam turbine unit and the series capacitor compensation power transmission network.

Further, in an embodiment of the present invention, the protection criterion module 400 is further configured to judge whether the transient torque identification value is greater than the second preset value; The current cycle torque peak value and the previous cycle peak value determine whether it is in a continuous growth state; if it is in a continuous growth state, a trip command is generated.

Further, in an embodiment of the present invention, the transient torque identification module 200 is further configured to convert the current modal rotational speed into a modal rotational speed signal of the shafting position corresponding to the torque; Integrate the rotational speed signal to obtain the torsion angle corresponding to each mode; convert the torsion angle corresponding to each mode into the electrical torsion angle of the mass relative to the synchronous rotating coordinate system; according to the electrical torsion angle of the mass relative to the synchronous rotating coordinate system Solve for torque between shaft segments.

Further, in an embodiment of the present invention, the conversion formula of the modal rotational speed signal is:

ω ^(m) = ω./k,

Among them, ω is the current modal speed, ./ is defined as the division of the corresponding elements of the matrix, and k is the coefficient row vector;

Integrate ω ^(m) to obtain the torsion angle δ ^(m) corresponding to each mode;

The conversion formula of the electrical torsion angle is:

[δ ₁ δ ₂ … δ _n-1 δ _n ] ^T = Q·[δ ₁ ^(m) δ ₂ ^(m) … δ _n-1 ^(m) 0] ^T ,

Among them, Q is the coefficient matrix, δ ^(m) is the torsion angle corresponding to each mode, and δ is the electrical torsion angle.

Further, in an embodiment of the present invention, the calculation formula of the torque between each shaft segment is:

T _ij =K _ij (δ _i -δ _j ),

Among them, K _ij represents the elastic coefficient between each shaft segment.

It should be noted that the foregoing explanation of the embodiment of the shafting speed-based transient torque protection method for a steam turbine unit is also applicable to the shafting speed-based transient torque protection device for a steam turbine unit, which will not be repeated here.

According to the embodiment of the present invention, the transient torque protection device for a steam turbine unit based on the shafting speed is based on the acquisition of the modal speed and the identification of the transient torque. First, use the filter to filter the shafting speed of the unit to obtain the modal speed of the unit; then, use the torque identification link to obtain the transient torque of the unit; finally, use the protection criterion to determine whether to send a trip command to disconnect the unit from the power grid Therefore, it can avoid the damage to the shaft system of the unit due to excessive torque, ensure the safety of the shaft system of the steam turbine generator set, and effectively solve the SSR problem between the steam turbine unit and the series capacitor compensation transmission network.

In addition, the methods and apparatuses of the embodiments of the present invention may be implemented by various methods in specific analysis, including but not limited to:

(1) Change the overall structure of the protection device in the present invention to other forms;

(2) adopting the filter design method different from the present invention to realize the acquisition of modal rotational speed;

(3) Use the shafting speed signal of other positions, such as the speed of the medium pressure cylinder, the speed of the low pressure cylinder, etc.;

(4) using circuits or/and various functional modules in various analysis software to form a model for realizing the present invention;

(5) Combined application of the above implementation methods.

On the basis of the technical solution of the present invention, any improvements and equivalent transformations made to the structure of each module inside the protection device according to the principles of the present invention should not be excluded from the protection scope of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (8)

1. A transient torque protection method of a turboset based on a shafting rotating speed is characterized by comprising the following steps:

filtering the rotating speed signal of the shafting of the unit by using a filter to obtain the current modal rotating speed of the unit;

transient torque identification is carried out by utilizing the current modal rotating speed to obtain a transient torque identification value, which specifically comprises the following steps:

converting the current modal rotating speed into a modal rotating speed signal of a shafting position corresponding to the torque;

integrating modal rotating speed signals of a shafting position corresponding to the torque to obtain a torsion angle corresponding to each mode;

converting the torsion angles corresponding to the modes into electric torsion angles of the mass relative to a synchronous rotation coordinate system;

solving the torque between the shaft sections according to the electric torsion angle of the mass relative to the synchronous rotating coordinate system;

if the current modal rotating speed is larger than a first preset value, judging whether a transient torque identification value is larger than a second preset value; and

and if the transient torque identification value is larger than a second preset value and is in a continuous increasing state, a tripping command is sent out to cut off the current unit.

2. The method of claim 1, wherein the step of issuing a trip command if the transient torque identification value is greater than a second predetermined value and in a continuously increasing state comprises:

judging whether the transient torque identification value is larger than the second preset value or not;

if the current cycle torque peak value is larger than the second preset value, delaying one cycle to judge whether the current cycle torque peak value is in a continuous increasing state or not according to the current cycle torque peak value and the previous cycle torque peak value;

and if the continuously increasing state is adopted, generating the tripping instruction.

3. The method of claim 1, wherein the modal speed signal is converted by the formula:

ω^(m)＝ω./k，

wherein, omega is the current mode rotating speed,/is defined as the division of the corresponding elements of the matrix, and k is the coefficient row vector;

for omega^(m)Integrating to obtain the torsion angle corresponding to each mode^(m)；

The conversion formula of the electric torsion angle is as follows:

[_{1 2}…_{n-1 n}]^T＝Q·[₁ ^(m) ₂ ^(m)…_n-1 ^(m)0]^T，

wherein Q is a coefficient matrix,^(m)the torsion angle corresponding to each mode is an electrical torsion angle.

4. The method of claim 3, wherein the torque between the shaft segments is calculated by the formula:

T_ij＝K_ij(_i-_j)，

wherein, K_ijRepresenting the spring constant between the shaft segments.

5. The utility model provides a turboset transient state moment of torsion protection device based on shafting rotational speed which characterized in that includes:

the modal rotating speed acquisition module is used for filtering the rotating speed signal of the shafting of the unit by using the filter to obtain the current modal rotating speed of the unit;

the transient torque identification module is used for identifying transient torque by using the current modal rotating speed to obtain a transient torque identification value, and the transient torque identification module is further used for converting the current modal rotating speed into a modal rotating speed signal of a shafting position corresponding to torque; integrating modal rotating speed signals of a shafting position corresponding to the torque to obtain a torsion angle corresponding to each mode; converting the torsion angles corresponding to the modes into electric torsion angles of the mass relative to a synchronous rotation coordinate system; solving the torque between the shaft sections according to the electric torsion angle of the mass relative to the synchronous rotating coordinate system;

the starting logic module is used for judging whether the transient torque identification value is larger than a second preset value or not when the current modal rotating speed is larger than a first preset value; and

and the protection criterion module is used for sending a tripping command to cut off the current unit when the transient torque identification value is larger than a second preset value and is in a continuous increasing state.

6. The apparatus of claim 5, wherein the protection criterion module is further configured to determine whether the transient torque identification value is greater than the second predetermined value; if the current cycle torque peak value is larger than the second preset value, delaying one cycle to judge whether the current cycle torque peak value is in a continuous increasing state or not according to the current cycle torque peak value and the previous cycle torque peak value; and if the continuously increasing state is adopted, generating the tripping instruction.

7. The apparatus of claim 5, wherein the modal speed signal is transformed by the formula:

ω^(m)＝ω./k，

wherein, omega is the current mode rotating speed,/is defined as the division of the corresponding elements of the matrix, and k is the coefficient row vector;

for omega^(m)Integrating to obtain the torsion angle corresponding to each mode^(m)(ii) a The conversion formula of the electric torsion angle is as follows:

[_{1 2}…_{n-1 n}]^T＝Q·[₁ ^(m) ₂ ^(m)…_n-1 ^(m)0]^T，

wherein Q is a coefficient matrix,^(m)the torsion angle corresponding to each mode is an electrical torsion angle.

8. The apparatus of claim 7, wherein the torque between the shaft segments is calculated by the formula:

T_ij＝K_ij(_i-_j)，

wherein, K_ijRepresenting the spring constant between the shaft segments.

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